Cyclic hypoxia exposure accelerates the progression of amoebic gill disease
Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans, has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved...
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ftdeakinunifig:oai:figshare.com:article/24603114 2024-09-09T19:30:34+00:00 Cyclic hypoxia exposure accelerates the progression of amoebic gill disease T Oldham Tim Dempster P Crosbie M Adams B Nowak 2020-08-01T00:00:00Z http://hdl.handle.net/10779/DRO/DU:24603114.v3 https://figshare.com/articles/journal_contribution/Cyclic_hypoxia_exposure_accelerates_the_progression_of_amoebic_gill_disease/24603114 unknown http://hdl.handle.net/10779/DRO/DU:24603114.v3 https://figshare.com/articles/journal_contribution/Cyclic_hypoxia_exposure_accelerates_the_progression_of_amoebic_gill_disease/24603114 CC BY 4.0 Biological sciences Microbiology Biomedical and clinical sciences Immunology Medical microbiology aquaculture Atlantic salmon dissolved oxygen Paramoeba/Neoparamoeba perurans Salmo salar stress Text Journal contribution 2020 ftdeakinunifig 2024-06-20T00:31:11Z Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans, has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved oxygen (DO) conditions are most common. Here, we tested if exposure to cyclic hypoxia at DO saturations of 40–60% altered the course of infection with N. perurans compared to normoxic controls maintained at ≥90% DO saturation. Although hypoxia exposure did not increase initial susceptibility to N. perurans, it accelerated progression of the disease. By 7 days post-inoculation, amoeba counts estimated from qPCR analysis were 1.7 times higher in the hypoxic treatment than in normoxic controls, and cumulative mortalities were twice as high (16 ± 4% and 8 ± 2%), respectively. At 10 days post-inoculation, however, there were no differences between amoeba counts in the hypoxic and normoxic treatments, nor in the percentage of filaments with AGD lesions (control = 74 ± 2.8%, hypoxic = 69 ± 3.3%), or number of lamellae per lesion (control = 30 ± 0.9%, hypoxic = 27.9 ± 0.9%) as determined by histological examination. Cumulative mortalities at the termination of the experiment were similarly high in both treatments (hypoxic = 60 ± 2%, normoxic = 53 ± 11%). These results reveal that exposure to cyclic hypoxia in a diel pattern, equivalent to what salmon are exposed to in marine aquaculture cages, accelerated the progression of AGD in post-smolts. Article in Journal/Newspaper Atlantic salmon Salmo salar DRO - Deakin Research Online |
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Open Polar |
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DRO - Deakin Research Online |
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ftdeakinunifig |
language |
unknown |
topic |
Biological sciences Microbiology Biomedical and clinical sciences Immunology Medical microbiology aquaculture Atlantic salmon dissolved oxygen Paramoeba/Neoparamoeba perurans Salmo salar stress |
spellingShingle |
Biological sciences Microbiology Biomedical and clinical sciences Immunology Medical microbiology aquaculture Atlantic salmon dissolved oxygen Paramoeba/Neoparamoeba perurans Salmo salar stress T Oldham Tim Dempster P Crosbie M Adams B Nowak Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
topic_facet |
Biological sciences Microbiology Biomedical and clinical sciences Immunology Medical microbiology aquaculture Atlantic salmon dissolved oxygen Paramoeba/Neoparamoeba perurans Salmo salar stress |
description |
Amoebic gill disease (AGD), caused by the amoeba Neoparamoeba perurans, has led to considerable economic losses in every major Atlantic salmon producing country, and is increasing in frequency. The most serious infections occur during summer and autumn, when temperatures are high and poor dissolved oxygen (DO) conditions are most common. Here, we tested if exposure to cyclic hypoxia at DO saturations of 40–60% altered the course of infection with N. perurans compared to normoxic controls maintained at ≥90% DO saturation. Although hypoxia exposure did not increase initial susceptibility to N. perurans, it accelerated progression of the disease. By 7 days post-inoculation, amoeba counts estimated from qPCR analysis were 1.7 times higher in the hypoxic treatment than in normoxic controls, and cumulative mortalities were twice as high (16 ± 4% and 8 ± 2%), respectively. At 10 days post-inoculation, however, there were no differences between amoeba counts in the hypoxic and normoxic treatments, nor in the percentage of filaments with AGD lesions (control = 74 ± 2.8%, hypoxic = 69 ± 3.3%), or number of lamellae per lesion (control = 30 ± 0.9%, hypoxic = 27.9 ± 0.9%) as determined by histological examination. Cumulative mortalities at the termination of the experiment were similarly high in both treatments (hypoxic = 60 ± 2%, normoxic = 53 ± 11%). These results reveal that exposure to cyclic hypoxia in a diel pattern, equivalent to what salmon are exposed to in marine aquaculture cages, accelerated the progression of AGD in post-smolts. |
format |
Article in Journal/Newspaper |
author |
T Oldham Tim Dempster P Crosbie M Adams B Nowak |
author_facet |
T Oldham Tim Dempster P Crosbie M Adams B Nowak |
author_sort |
T Oldham |
title |
Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
title_short |
Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
title_full |
Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
title_fullStr |
Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
title_full_unstemmed |
Cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
title_sort |
cyclic hypoxia exposure accelerates the progression of amoebic gill disease |
publishDate |
2020 |
url |
http://hdl.handle.net/10779/DRO/DU:24603114.v3 https://figshare.com/articles/journal_contribution/Cyclic_hypoxia_exposure_accelerates_the_progression_of_amoebic_gill_disease/24603114 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_relation |
http://hdl.handle.net/10779/DRO/DU:24603114.v3 https://figshare.com/articles/journal_contribution/Cyclic_hypoxia_exposure_accelerates_the_progression_of_amoebic_gill_disease/24603114 |
op_rights |
CC BY 4.0 |
_version_ |
1809899569665802240 |